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Page last reviewed: 13/07/2011

Chemotherapy is the use of drugs to treat cancer.


The term cancer refers to a number of conditions where some of the body's cells grow and reproduce uncontrollably. The rapid growth of cancerous cells is known as a malignant tumour. These cells can invade and damage or destroy healthy tissue and organs.

Cytotoxic medication

In the past, any medication that killed/slowed the growth of cancerous cells was called chemotherapy. In recent years, new cancer medications have been introduced that work differently from traditional chemotherapy.

Today, when health professionals talk about chemotherapy medication, they are specifically talking about cytotoxic medication. Cytotoxic refers to medication that prevents cancer cells from dividing and growing.

The aims of chemotherapy

Chemotherapy is used for a number of different reasons, including:

  • To achieve a complete cure. In some cases, it may be possible to kill all the cancer cells using chemotherapy alone.
  • To help make other treatments more successful. For example, chemotherapy imay be combined with radiotherapy.
  • To reduce the risk of cancer returning i.e. in a preventative fashion. For example some people are given a course of chemotherapy after surgery has removed a cancer.
  • To relieve symptoms. If a cancer is diagnosed at an advanced stage where it cannot be surgically removed chemotherapy may be used to attempt to relieve symptoms and slow the cancer's spread.

Side effects

Chemotherapy is an effective itreatment for cancer and has helped save millions of lives but does have side effects.

Side effects occur because the medication used in chemotherapy cannot distinguish between fast-growing cancer cells and other types of fast-growing cell, such as blood cells, the cells on the skin and scalp and the cells inside the stomach.

Some people who are about to begin chemotherapy are concerned that any harmful affects of chemotherapy can be passed on to other people, particularly those who are vulnerable such as children or pregnant women. However, there is no risk in coming into close contact with someone having chemotherapy.

Living with and adapting to the side effects of chemotherapy can be challenging, but it is important to realise that most, if not all, side effects will disappear once treatment is complete.

See the Side effects section, above, for more information and advice about how to cope with the side effects of chemotherapy.

Chemotherapy is the treatment of an illness or disease with a chemical substance, for example in the treatment of cancer.
Cytotoxic medicine is used to treat cancer.
Radiotherapy uses X-rays to treat disease, especially cancer.

Page last reviewed: 13/07/2011

The principle behind chemotherapy was discovered during World War Two when a number of sailors were accidentally exposed to mustard gas. When they were treated in hospital, doctors noticed that the sailors had an unusually low number of white blood cells. White blood cells are similar to cancer cells in that they divide and grow rapidly.

Doctors reasoned that if the chemicals in mustard gas reduced the number of white blood cells by stopping them growing, they could have the same effect on cancer cells. Testing showed they were right.

Over time, the chemicals used in chemotherapy were improved and more efficient medications were created.

There are now over 50 different types of chemotherapy medication to treat hundreds of different cancers.

Depending on the type of cancer, you may be given:

  • monotherapy, where only one chemotherapy medication is used, or
  • combination therapy, where more than one medication is used

When should chemotherapy be given?

Depending on the type and severity of your cancer, chemotherapy is given at different stages of treatment.

You may receive chemotherapy:

  • before undergoing surgery or radiotherapy to shrink the tumour before other treatments begin (neoadjuvant therapy)
  • in combination with radiotherapy (chemoradiation), or
  • after surgery or a course of radiotherapy (adjuvant therapy)

Chemotherapy protocols

In general chemotherapy is given over a set period of time for it to be effective. Your chemotherapy care team will draw up a protocol that outlines how often you will receive treatment and for how long.

Chemotherapy protocols vary depending on the type of cancer that you have and how advanced it is.
An example of a chemotherapy protocol is:

  • one day of treatment
  • six days of rest
  • one day of treatment, and
  • 21 days of rest

This cycle could be repeated six times over the course of 18 weeks.

Page last reviewed: 13/07/2011

Your care team

Many hospitals have multidisciplinary teams (MDTs) who treat cancer. An MDT is made up of a number of different specialists, including:

  • A medical oncologist: a specialist in the non-surgical treatment of cancer using medications
  • A radiation oncologist: a specialist in the non-surgical treatment of cancer using radiotherapy
  • A pathologist: a specialist in diseased tissue.
  • A haematologist: a blood specialist.
  • A cancer nurse, who will usually be your first point of contact with the MDT.
  • A psychologist, who can provide support and advice about the psychological and emotional impact of chemotherapy (Very few MDT's have a full time psychologist as part of their team)

You may see some or all of these people as part of your cancer treatment.

Blood tests

Before chemotherapy begins, you will need a number of blood tests to assess your health and to make sure you will be able to cope with any side effects.

Blood tests are a useful way of assessing the health of your liver and your kidneys. This is important because the chemotherapy medications will pass through your liver and your kidneys where they will be broken down. The medication can harm the liver and the kidneys so if you have liver or kidney damage it may not be suitable for you until your liver or kidneys have recovered.

Another important role of blood testing is to assess your blood count. This is a measurement of how many blood cells you have.

There are three types of blood cell:

  • red blood cells, which carry oxygen around your body
  • white blood cells, which fight infection, and
  • platelets, which help the blood to clot (solidify)

Chemotherapy reduces the number of all three types of blood cells. 

If you have a low blood count, treatment may be delayed or deferred until your blood count has returned to normal.

You will have regular blood tests during your chemotherapy so that your liver, kidney and blood count are carefully monitored.

You may need other tests to check how well the cancer is responding to treatment. The tests you require will depend on the type of cancer you have.

How is chemotherapy given?

Chemotherapy is usually given in one of two ways:

  • in tablet form (oral chemotherapy), or
  • directly into one your veins using an injection or a drip (intravenous chemotherapy)

The type of chemotherapy you have depends on the type of cancer.

Oral chemotherapy

You may be able to take your tablets at home. You will still have to make regular hospital visits for check-ups.

It is very important that you take your tablets on the days that are specified in your chemotherapy protocol. If you forget to take a tablet, contact your care team for advice. Also contact your care team if you are sick shortly after taking a tablet.

Intravenous chemotherapy

There are a number of different devices that can deliver chemotherapy medications into a vein.


A cannula is a small tube that is placed into a vein on the back of your hand or lower arm. Chemotherapy medication is slowly injected through the tube into your vein. Once the dose of medication has been delivered, the tube can be removed.

Skin-tunnelled catheter

A skin-tunnelled catheter is a fine tube that is inserted into your chest and connected to one of the veins near your heart. The catheter can be left in place for several weeks or months, so you do not have to have repeated injections. The catheter can also be used to carry out blood tests.

Peripherally inserted central catheter

A peripherally inserted central catheter (PICC) is similar to a skin-tunnelled catheter except the tube is connected to your arm rather than your chest.

Implanted port

An implanted port is a chamber that can be inserted under your skin and connected to a nearby vein. A special needle is placed into the chamber and connected to a drip or used for blood tests.

The type of device used often depends on the type of cancer you have and your general state of health.

The time it takes to administer one dose can range from several hours to several days.

Occasionally, some people need a continuous low dose of chemotherapy medication over the course of several weeks or months. If this is the case, you may be given a small portable pump that you can take home with you.

Other medication

If you are having chemotherapy, check with your care team before taking any other type of medication, including over-the-counter (OTC) medication and herbal remedies. Other medication could interfere with your chemotherapy medication.


If you are a sexually active woman, avoid becoming pregnant while having chemotherapy. Many medications used in chemotherapy can cause birth defects.

You will need to use a barrier method of contraception, such as condoms, while having chemotherapy and for a year after your treatment has finished.

Contact your care team straight away if you think you may have become pregnant during chemotherapy.

Page last reviewed: 13/07/2011

It is difficult to predict exactly what side effects you will experience while having chemotherapy because different people react to treatment in different ways. Some people experience very few side effects.

The common side effects of chemotherapy are listed below. It is unlikely that you will experience all the side effects listed.

Your care team is there to help you cope with the physical and psychological side effects.

When to seek urgent medical advice

While they are distressing, most side effects of chemotherapy are not a serious threat to your health. Occasionally, some side effects can be very serious.

Symptoms that may suggest you have a serious side effect include:

  • a high temperature (fever) of 38°C (100.4°F) or above
  • shivering
  • breathing difficulties
  • flu-like symptoms, such as muscle aches and pain
  • bleeding gums or nose
  • bleeding from other parts of the body that does not stop after applying pressure  for 10 minutes
  • mouth ulcers that stop you eating or drinking
  • vomiting that continues despite taking anti-sickness medication
  • four or more bowel movements a day or diarrhoea

If you experience any of these symptoms, contact your care team or GP immediately.


Fatigue is a common side effect of chemotherapy. Almost everyone who has chemotherapy will experience fatigue. You may feel generally tired, or you may tire very easily after carrying out everyday tasks.

While having chemotherapy, it is important to get plenty of rest and not to do any activities that you do not feel up to.

Light exercise, such as walking or yoga, can help boost your energy levels, but be careful not to push your body too hard.

If you are working, you may need to ask your employer if you can work part-time until your chemotherapy has finished.

If you suddenly find yourself significantly more tired than usual, contact your care team. Extreme fatigue can be a sign of anaemia, which is caused by having a low number of red blood cells (see below for more details).

Nausea and vomiting

Nausea and vomiting are common side effects of chemotherapy. An estimated 60% of people who have chemotherapy will feel sick and 50% will experience vomiting.

If you have nausea and vomiting, you will be given medication to control your symptoms. This is known as an anti-emetic.

You should continue to take your anti-emetics even if you do not feel sick because they will help prevent your symptoms from returning.

Contact your care team if you continue to experience nausea and vomiting despite taking anti-emetics. Different types of anti-emetic are available and different people find some more effective than others.

Hair loss

Hair loss is a common side effect of chemotherapy. Not all chemotherapy medications cause hair loss and sometimes the hair becomes thin and brittle rather than falling out.

If hair loss does occur, it usually begins within a few weeks of starting treatment. Hair loss can happen anywhere on the body including:

  • head
  • arms
  • legs
  • face
  • armpits
  • pubic region

People who have never experienced chemotherapy-related hair loss can underestimate how traumatic it is, particularly for women.

If you find your hair loss particularly hard to cope with, talk to your care team. They understand how distressing it can be and will be able to give you support and counselling.

You may decide that you want to wear a wig.

It is important to remember that hair loss is always temporary and your hair will begin to grow back soon after your treatment has finished.

Cold cap

It may be possible to prevent chemotherapy-associated hair loss by using a cold cap.

A cold cap looks similar to a bicycle helmet and is designed to cool your scalp while you receive a dose of chemotherapy. In cooling the scalp, the cold cap reduces the amount of bloodflow to the scalp, which reduces the amount of chemotherapy medication that reaches it.

Whether or not you can use a cold cap during treatment will depend on the type of cancer you have. For example, if you have leukaemia, there may be cancer cells near your scalp so a cold cap cannot be used.

Cold caps work better with certain chemotherapy medications than others and they may not always prevent hair loss.

Vulnerability to infection

Chemotherapy lowers the amount of white blood cells. The main function of white blood cells is to fight infection. If the number of white blood cells is reduced, your immune system will be weakened and you will be more vulnerable to infection.

You may be given a course of antibiotics to reduce your risk of developing an infection. You will also need to take extra precautions to protect yourself against infection.

  • Practise good personal hygiene. Take daily baths or showers and make sure that clothes, towels and bed linen are washed regularly.
  • Avoid contact with people with serious infections, such as chicken pox or flu.
  • Wash your hands regularly with soap and hot water, particularly after going to the toilet and before preparing food and eating meals.
  • Take extra care not to cut or graze your skin. If you do, clean the area thoroughly with warm water, then dry it and cover it with a sterile dressing.

If you develop an infection, you may need to be admitted to hospital and treated with intravenous antibiotics (antibiotics that are injected directly into a vein).


Chemotherapy will lower your amount of red blood cells. Red blood cells carry oxygen around the body. If your red blood cell count drops too low, your body will be deprived of oxygen and you will develop anaemia.

Symptoms of anaemia include:

  • tiredness (you will feel much more tired than the general level of fatigue associated with chemotherapy)
  • lack of energy
  • shortness of breath (dyspnoea)
  • irregular heartbeat

If you experience any of these symptoms, contact your care team as soon as possible.

You may need a blood transfusion to help increase the number of red blood cells. Alternatively, a medication called erythropoietin (EPO) can stimulate the production of red blood cells.

It is important to eat a diet that is high in iron because iron helps red blood cells carry more oxygen. Foods that are high in iron include:

  • dark green leafy vegetables (such as spinach)
  • iron-fortified bread
  • beans
  • nuts
  • meat
  • apricots
  • prunes
  • raisins

Bruising and bleeding

Chemotherapy can lower the amount of platelets in your body.

Platelets are blood cells that help blood to clot to prevent excessive bleeding or bruising.

Most chemotherapy medications do not seriously affect the number of platelets, although a small number of people experience a significant drop in their platelet count.

Symptoms of a low platelet count include:

  • easily bruised skin
  • nose bleeds
  • bleeding gums

Report any of the above symptoms to your care team as you may need a blood transfusion to raise your platelet count.

You may need to take extra precautions to avoid damaging your skin and gums, including:

  • using an electric razor to shave
  • using a soft toothbrush
  • taking extra care when using knives or other sharp instruments
  • wearing a thick pair of gloves when gardening

Oral mucositis

In some cases, chemotherapy can cause pain and inflammation of the surface of the inside of your mouth. This is known as oral mucositis.

The severity of your symptoms usually depends on the strength of your medication.

People having high-dose chemotherapy usually experience more severe symptoms.

Symptoms of oral mucositis usually begin between seven and 10 days after you start your chemotherapy treatment.

If you develop oral mucositis, the tissue inside your mouth will begin to feel sore, as if you have burnt it by eating very hot food. You will probably develop ulcers on the lining of your mouth and, in some cases, on your tongue and on or around your lips.

The ulcers can be very painful and make it difficult for you to eat, drink and talk. They may also bleed and become infected.

The symptoms of oral mucositis should clear up a few weeks after your chemotherapy has finished.

A number of different medications are available to relieve the symptoms of oral mucositis. See Useful links for more information.

Loss of appetite

Some people who have chemotherapy lose their appetite and do not feel like eating or drinking. If you lose your appetite, it is still important to make an effort to eat healthily and drink plenty of liquids.

You may find that eating smaller, more frequent meals is better than eating three large meals a day. Try sipping drinks slowly through a straw rather than drinking them straight from a glass or cup.

If you experience serious problems eating and drinking due to symptoms such as mouth ulcers, you may need to be admitted to hospital and attached to a feeding tube.

You will probably be given a nasogastric tube, which is a tube that passes down your nose and into your stomach. The tube can be removed once you are able to eat and drink normally.


Some chemotherapy medications can cause your skin to become dry and sore, particularly on your hands or feet. You may notice that your nails become brittle and flakier than usual and that white lines develop across the nails.

During chemotherapy, and for some time after your treatment has finished, your skin may become more sensitive to sunlight. It is important to take extra precautions to protect your skin from the sun.

  • Avoid the sun when it is at its hottest, usually between 10am and 2pm (although the sun can also be damaging to skin before and after these times).
  • Use a sunscreen that blocks both ultraviolet A (UVA) and B (UVB) radiation and has a sun protection factor (SPF) of at least 15.
  • Dress in a way that protects your skin from the sun. For example, wear a wide-brimmed hat to protect your face and scalp and sunglasses to protect your eyes.

Memory and concentration

Some people on chemotherapy have problems with their short-term memory, concentration and attention span. You may find that doing routine tasks takes a lot longer than usual.This is often called "chemo brain".

Exactly why these symptoms appear is uncertain. They may be due to a combination of factors such as fatigue and anxiety. 

The symptoms tend to improve once your treatment has finished but may take time.

Sexuality and fertility

Many people find that their libido (interest in sex) diminishes during chemotherapy. Loss of libido is usually temporary and your interest in sex should gradually return once your treatment has finished.

Some chemotherapy medications can stop women being able to conceive and can prevent men from producing healthy sperm. Loss of fertility is usually temporary, although in some cases a person can become permanently infertile.

If there is a risk that you could become permanently infertile, your care team will discuss the possibility with you before treatment begins. 

A number of options are available. Women can have their embryos frozen to be used later in IVF (in-vitro fertilisation).

Men can have a sample of their sperm frozen to be used at a later date for artificial insemination.

See Useful links for more information about IVF and artificial insemination.

Diarrhoea and constipation

You may experience diarrhoea or constipation a few days after you begin chemotherapy.

Your care team can recommend suitable medication to help control the symptoms.


Living with the effects of chemotherapy can be frustrating, stressful and traumatic. It is natural to feel ongoing anxiety and concern about whether your treatment will be successful.

Stress and anxiety can increase your risk of getting depression. You may be depressed if you have been feeling particularly down for two weeks or more and you no longer take pleasure in the things you used to enjoy.

If you are experiencing psychological and emotional difficulties, contact your care team. They can recommend treatments to help improve the symptoms of stress, anxiety and depression.

Joining a support group for people who are having chemotherapy may also help. Talking to other people in a similar situation can often reduce feelings of isolation and stress.

See Useful links for more information about what support groups are available.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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